Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/workbox-strategies/CacheOnly.d.ts

@@ -0,0 +1,26 @@
+import { Strategy } from './Strategy.js';
+import { StrategyHandler } from './StrategyHandler.js';
+import './_version.js';
+/**
+ * An implementation of a [cache-only](https://developer.chrome.com/docs/workbox/caching-strategies-overview/#cache-only)
+ * request strategy.
+ *
+ * This class is useful if you want to take advantage of any
+ * [Workbox plugins](https://developer.chrome.com/docs/workbox/using-plugins/).
+ *
+ * If there is no cache match, this will throw a `WorkboxError` exception.
+ *
+ * @extends workbox-strategies.Strategy
+ * @memberof workbox-strategies
+ */
+declare class CacheOnly extends Strategy {
+    /**
+     * @private
+     * @param {Request|string} request A request to run this strategy for.
+     * @param {workbox-strategies.StrategyHandler} handler The event that
+     *     triggered the request.
+     * @return {Promise<Response>}
+     */
+    _handle(request: Request, handler: StrategyHandler): Promise<Response>;
+}
+export { CacheOnly };